Chinese brake fern (Pterisvittata) as the hyperaccumulator of arzenic at tailing dams of the Zambian Copperbelt

Geoscience Research Reports 42, 2009 (GRR for 2008), pages 218–221

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Abstract

Waterlogged and semi-dry parts of tailing dams after processing of copper and cobalt ores in Zambia are predominantly growing over by papyrus (Cyperus papyrus) and Chinese brake fern (Pteris vittata L). The tailings are very rich in copper (up to 0.8 wt.%) and cobalt (up to 0.25 wt.%). The amount of arzenic in tailings ranges between 0.24 and 180 ppm. Very high contents of arzenic in fern fronds (up to 6 197 ppm in dry matter) do not correlate with the amount and speciation of arzenic in tailings. Concentration of arzenic in leaves of papyrus, which is growing at same positions as fern, is much lower (9-30 ppm). The average concentrations of copper, cobalt and zinc are very similar in both plants. Results of this study demonstrate that the Chinese brake fern hyperaccumulates not only arzenic but can tolerate very high concentrations of other metals in substrate.